Résumé
Among mechanical systems, a large number presents naturally a divided feature: granular media, masonries, metal at the grain level, etc. Some of them, due to external loading, may evolve from a continuous state to a, globally or locally, divided one: fracture, wear, cracks, etc. When numerical studies of such media are performed, Discrete Elements Methods (DEMs) appear as most appropriate tool to face to different problems. Classically, DEMs are based on some hypotheses concerning contact area, deformations and contact interactions which are in some circumstance questionable, especially when they have a strong influence on the macroscopic behaviour of the media. Using the Contact Dynamics framework, the paper presents how classical hypothesis could be extended to avoid numerical effects. A reflection is proposed taking into account both physical and numerical aspects. Static and dynamic configuration have been used to illustrate the paper purposes.